Mechanical pool cleaners are typically classified as pressure-side cleaners or suction-side cleaners based on their connection to a pool pump. More specifically, suction-side pool cleaners are connected to a suction or inlet port of the pump, while pressure-side pool cleaners are connected to a pressure or outlet port of the pump. In both types, water is drawn or forced through the cleaner and mechanisms are provided to attempt to harvest energy from water movement through the cleaner in order to operate one or more functions of the cleaner (e.g., vacuuming, steering, etc.).
With respect to suction-side pool cleaners, a turbine or paddle wheel may be provided within a water flow passage to harvest energy from the water flow. Generally, design aspects of the paddle wheel and related components are based on a tradeoff between performance and efficiency. For example, reducing the clearances between blades of the paddle wheel and the walls of the associated flow passage may increase efficiency by allowing the paddle wheel to harness more kinetic energy from the fluid flow. However, reduced clearance may detrimentally affect paddle wheel performance because debris may not be allowed to pass through the water flow passage, and/or may impede rotation of the paddle wheel. On the other hand, increasing the clearances may improve performance by allowing debris to pass through the passage without impeding the paddle wheel. In this instance, however, more fluid may flow through the larger clearances without providing kinetic energy to the paddle wheel, which may result in reduced efficiency.
One pool cleaning system includes a pool cleaner with a primary turbine and two secondary turbines. The primary turbine is mounted to a primary shaft and is fed by a primary fluid inlet. Fluid flow from the primary fluid inlet causes the primary turbine to rotate, thereby causing movement of the pool cleaner via walking pods. The secondary turbines are separately mounted to secondary shafts that are distinct from the primary shaft, and are fed by a secondary fluid inlet. Fluid flow from the secondary fluid inlet causes the secondary turbines to rotate in order to provide torque to a suction hose. Among other drawbacks, the use of separate turbines on separate shafts may not appropriately address the handling of debris to optimize performance and efficiency.
Another pool cleaning system includes a first turbine receiving fluid flow from an external flow generator to drive rotation of a drive shaft. Rotation of the drive shaft drives rotation of a second turbine, which acts as an internal flow generator to expel water from the system.
A further pool cleaning system includes two distinct vortex chambers for generating a swirling pattern of fluid flow within the chambers. Two turbines of the same type (i.e., of the same shape and size) are provided, with one turbine being oriented in each chamber at a location that is removed from the direct flow of fluid through the chamber. Fluid flow from an inlet is equally divided between the two chambers, with the swirling flow pattern within the chambers driving rotation of the turbines. The turbines are supported by independent shafts, with one of the turbines providing motive power to a first drive wheel of the system and the other turbine providing motive power to a second drive wheel of the system. Among other drawbacks, removal of turbines from the direct flow path of a fluid flow may result in reduced system efficiency. Further, the use of two turbines of the same type may not assist in the handling of debris to optimize performance and efficiency.